This invention relates to hook units and, more specifically, to hook units usable to position and retain in place a fabric cover, such as a cover for a swimming pool.
In many areas residential swimming pools, such as in-ground pools, are in use for only part of each year. During periods of non-use it is common to provide a sturdy fabric cover positioned over the open area of the pool, particularly to prevent children from falling into an unattended pool and to limit entry of debris into the water.
A pool cover may be constructed of strong fabric resistant to degradation in the presence of moisture, sunlight and other environmental factors. A cover may be porous or have a drainage configuration to mitigate the buildup of water from rain and snow, while still limiting the passage of debris into the pool cavity below the cover which will typically contain water even during periods of non-use.
A variety of arrangements have been proposed for securely retaining a cover in place over a pool. In particular, a common objective is to retain the edges of the pool cover securely in close adjoining relationship to the sides or walls of the pool, so as to reduce the potential for gaps between the cover and the pool wall which could permit entry of a child or debris past the cover and into the pool cavity.
Hooks for pool cover applications may take the form of a hook to go through an eyebolt extending from the side wall of a swimming pool, with the hook fixed to a base plate attached to the lower surface of the pool cover fabric adjacent an edge. In some instances, an eyebolt may not be at a position accurately aligned with the position of the corresponding hook attached to the pool cover fabric, or an eyebolt may become somewhat bent to one side during the time when the pool cover is not installed. In such circumstances a fixed-position hook cannot be adjusted for the lateral discrepancy in eyebolt position and when attached the cover may be rippled or distorted. Also, in general, a hook may be subject to being unhooked from its position through an eyebolt if the hook assembly has inadequate provision for preventing the hook from being inadvertently removed from the eyebolt. Further, for a hook assembly which does not have a flat surface positionable against the pool cover, edges or protrusions from such surface may undesirably facilitate wear points or cuts to the pool cover fabric under adverse wind, contact or other conditions occurring after installation.
While a variety of hook designs have been proposed for cover retention, full structural reliability, cover protection, ease of use and adaptability to different configurations of installation have generally not been achieved by prior hook designs.
Objects of the present invention are to provide swivel hook units of improved configuration and hook units which may avoid one or more disadvantages or shortcomings of previously available hooks, such as prior hooks intended for use with fabric covers.